Chennai: Charging Karnataka with "unjustly utilising" Cauvery water for summer irrigation, Tamil Nadu Chief Minister Jayalalithaa on Saturday asked Prime Minister Manmhohan Singh to convene a meeting of the Cauvery River Authority to discuss the issue.

Karnataka has been "unjustly utilising" the water for summer irrigation from February to May by depleting storage in its four major reservoirs, she said in a letter to Singh.

The combined gross storage in the four major reservoirs of Karnataka as on February 1, 2012, was 58.50 TMC ft and on May 14, it was 28.176 TMC ft, Jayalalithaa claimed.

"Karnataka had depleted a storage of about 30.33 TMC ft. from 1.2.2012 to 14.5.2012, besides utilizing the flows of about 11 TMC ft." Thus, the total utilization during the period was about 41 TMC ft, she said.

Due to depletion of storage during summer, Karnataka "impounds" initial monsoon flows in its dams and released water only when they become surplus, she said, adding, this affected inflows into Mettur Dam in Tamil Nadu.

"This consequently affects Kuruvai (short term) crop very badly and also delays cultivation of Samba (long term) crop in the state", she said.

She said a solution was eluding the finalisation of Distress Sharing Formula evolved by Central Water Commission, ultimately depriving Tamil Nadu of adequate water which should have been released by Karnataka either as per Cauvery Water Disputes Tribunal`s interim order or by the formula evolved.

The Cauvery Monitoring Committee in its 24th meeting had decided to refer the formula to the Cauvery River Authority for consideration when noticeable distress condition occurs in future. "Such a distress situation may arise at any time."

She alleged that Karnataka was also not furnishing year-wise details of the area under irrigation though the Tribunal`s interim order specifies that Karnataka shall not increase its area under irrigation beyond 11.20 lakh acres.

Asking Singh to convene the meeting of the Authority, Jayalalithaa said the issue of notifying the Tribunal`s final order in the central gazette should also be discussed.